Deletion of FHL2 in fibroblasts attenuates fibroblasts activation and kidney fibrosis via restraining TGF-β1-induced Wnt/β-catenin signaling
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Four-and-a-half LIM domains protein 2 (FHL2) has been proposed involving in β-catenin activity. We previously reported that FHL2 mediates TGF-β1-induced tubular epithelial-to-mesenchymal transition through activating Wnt/β-catenin signaling. However, the potential role and mechanism for FHL2 in TGF-β1-induced fibroblast activation and kidney fibrosis remains unknown. Here, we initially observed higher levels of FHL2 expression in fibrotic kidneys from both patients and mice, especially in α-smooth muscle actin (α-SMA)-positive cells in the interstitium. In cultured interstitial fibroblasts, FHL2 expression was induced by TGF-β1. Knockdown of FHL2 remarkably suppressed TGF-β1-induced α-SMA, type I collagen, and fibronectin expression, while overexpression of FHL2 was sufficient to activate fibroblasts. In mice, fibroblast-specific deletion of FHL2 diminished renal induction of α-SMA, type I collagen, and fibronectin and interstitial extracellular matrix deposition at 2 weeks after ureteral obstruction. We next investigated Wnt/β-catenin activity and found that β-catenin was activated in most FHL2-positive cells in renal interstitium from mice with obstructive nephropathy. In vitro, TGF-β1 induced a physical interaction between FHL2 and β-catenin, especially in the nucleus. Downregulation of FHL2 inhibited TGF-β1-induced active β-catenin upregulation, β-catenin nuclear translocation, and β-catenin-mediated transcription, whereas overexpression of FHL2 was able to activate Wnt/β-catenin signaling. FHL2 overexpression-induced β-catenin-mediated gene transcription could be hindered by ICG-001, but FHL2 overexpression-induced upregulation of active β-catenin could not be. Collectively, this study reveals that the signal regulatory effect of FHL2 on β-catenin plays an important role in TGF-β1-induced fibroblast activation and kidney fibrosis.
KeywordsFHL2 β-Catenin TGF-β1 Fibroblast Kidney fibrosis
HW designed the study and wrote the paper. DY, QY and HX performed the experiments. HW, DY, and QY prepared all figures and analyzed the results. DC and YJ provided valuable suggestions and comments on the study design. All authors approved the final version of the manuscript.
This work was supported by National Natural Science Foundation of China (31571169/C110201 and 81170659/H0509) and Key Medical Talent in Science & Education Health Project of Jiangsu Province (ZDRCC2016006) to HW.
Compliance with ethical standards
Conflict of interest
The authors declared that they have no conflict of interest.
Animal protocol was approved by the Institutional Animal Care and Use Committee at the Nanjing Medical University. Study involving human tissues was approved by the Ethics Committee at the Second Affiliated Hospital of Nanjing Medical University.
- 42.Zhou B, Liu Y, Kahn M, Ann DK, Han A, Wang H, Nguyen C, Flodby P, Zhong Q, Krishnaveni MS, Liebler JM, Minoo P, Crandall ED, Borok Z (2012) Interactions between beta-catenin and transforming growth factor-beta signaling pathways mediate epithelial-mesenchymal transition and are dependent on the transcriptional co-activator cAMP-response element-binding protein (CREB)-binding protein (CBP). J Biol Chem 287(10):7026–7038PubMedPubMedCentralCrossRefGoogle Scholar
- 44.Choi JH, Zhong X, McAlpine W, Liao TC, Zhang D, Fang B et al (2019) LMBR1L regulates lymphopoiesis through Wnt/β-catenin signaling. Science 364(6440). Pii: eaau0812Google Scholar
- 45.Tan K, Xie X, Shi W, Miao L, Dong X, Yang W et al (2019) Deficiency of canonical Wnt/β-catenin signalling in hepatic dendritic cells triggers autoimmune hepatitis. Liver Int [Epub ahead of print] Google Scholar